Floyd Mayweather, left, puts his unblemished 44-0 record on the line when he fights Canelo Alvarez in Las Vegas.

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Floyd Mayweather faces Canelo Alvarez on Saturday in a battle of undefeated fighters

Mayweather is 44-0 with 26 knockouts and Alvarez is 42-0-1 with 30 knockouts

Mayweather is guaranteed to earn $41.5 million, the biggest payday in the sport's history

Oscar De La Hoya, Alvarez's promoter, will be absent in Las Vegas as he entered rehab

"Unbelievable" and an "explosion" is how Floyd Mayweather is selling his tangle with Saul 'Canelo' Alvarez in Las Vegas.

Whether Mayweather's ambitious billing of the bout will transpire remains to be seen, but what is not in doubt is the fight will generate the biggest purse in boxing history -- $41.5 million for Mayweather, already one of the world's highest-paid athletes.

The man regularly described as the best pound-for-pound fighter will earn even more cash Saturday in the sport's showbiz home by claiming a share of pay-per-view takings.

"This fight is truly unbelievable," Mayweather, who briefly unseated Tiger Woods as Forbes' best-paid athlete, in 2012, told CNN. "Man, this is all excitement. Canelo is young, strong, dedicated to his craft. I'm a legend in the sport.

"Canelo wants that No. 1 spot. Myself, I want to remain at the top. So it'll be an explosion."

Alvarez, promoted by one of Mayweather's past arch-rivals, Oscar De La Hoya, is the latest challenger to attempt to end the 36-year-old's unblemished record.

De La Hoya, Ricky Hatton, Arturo Gatti and Miguel Cotto are among those who have been unable to down the technically proficient American, while a Mayweather-Manny Pacquiao blockbuster has yet to materialize.

But Alvarez comes in undefeated, too, compiling a record of 42 victories and a draw.

The 23-year-old has registered more knockouts than Mayweather, 30 to 26, although the Mexican's foes are generally considered inferior.

"Canelo is a good boxer," Mayweather said. "He's strong, he's a good puncher. He's done things right to be undefeated at such a young age.

"But I think it's going to be very, very difficult for him come Saturday."

Alvarez isn't fazed, even if he is expected to weigh in at 152 pounds, a fraction lighter than usual.

"I don't care about his record," Alvarez was quoted as saying by Britain's Guardian newspaper. "I'm not coming to make a good fight, I'm coming to win.

"When you fight Floyd you have to be ready for every aspect of the fight. You have to be able to adjust mentally as well as physically.

"I have to be very smart and ready to change my plan at any time. You'll see how I do it. You'll see how I beat him. I'm calm and I'm just ready to fight."

If things go as planned, Mayweather will keep on winning. He is a 1/3 favorite with British bookmaker William Hill.

When asked what his place in boxing history was, the five-division world champion wasn't about to turn humble.

"Right now they call me 'TBE.' That's 'the best ever,'" he said. "The only thing I have to keep on doing is beating these young lions, keep beating the fighters they put in front of me and hopefully I'll go down as the best."